Blinds are widely used all over the world for their light-blocking and decoration functions. There are two typical types of traditional blinds, horizontal and vertical. Normally, they are hung behind the window on the indoor side and light passing through the blinds can be adjusted through adjusting the angle of rotation of the blind blades from totally light-blocking to totally light-transmitting. Blades of a blind also can be piled to one side of the window area when they are not being used.